Link chain



June 13, 1967 v E. w. ONULAK LINK CHAIN 4 Sheets-Sheet 1 Filed NOV. 18,1963 INVENTOR.

LAK

ATTORNEYS EUGENE W. ONU

FIG.

June 13, 1967 E. w. ONULAK 3,324,737

LINK CHAIN Filed Nov. 18, 1965 V 4 Sheets-Sheet 2 FIG. 3

IN VENTOR.

EUGENE W. ONULAK ATTORNEYS June 13, 1967 E. w. ONULAK 3,324,737

' LINK CHAIN Filed Nov. 18, 1963 4 Sheets-Sheet s F IG. 5

IN VEN TOR.

EUGENE W. ON ULAK BY 794%? $423k AT TORNEYS June 13, 1967 5 w, ONULAK3,324,737

LINK CHAIN Filed NOV. 18 1963 4 Sheets-Sheet 4 FIG. I54

54, INVENTOR. [6O BYEUGENE W. ONULAK mfi g g ATTORNEYS United StatesPatent 3,324,737 LINK CHAIN Eugene W. Onulak, P.O. Box 631, Huntington,Ind. 46750 Filed Nov. 18, 1963, Ser. No. 324,482 6 Claims. (Cl. 74-255)The present invention relates to a link chain and more particularly to achain of this type for use with sprockets in power transmissions and forconveyors.

Link chains have been and are extensively used in the power transmissionfield and for conveyors, and the conventional chain used in this fieldconsists basically of two spaced parallel side bars with connectingbushings forming one link and two spaced parallel side bars disposedexternally of said first bars and pivotally connected by pins at eachend of the links of the first type. The bushings engage the teeth of thedrive and driven sprockets, and links formed by the respective side barspivot on the interconnecting pins as the chain traverses the peripheriesof the various drive and driven sprockets. In this operation, thebushing inherently slidably engages the sprocket teeth, and frictioncreated between the teeth and bushing causes substantial wear on thebushing, eventually requiring repair or replacement of the chain. Theforegoing type of conventional link chain has wide application in manyfields, including the industrial, commercial, farm and domesticmachinery, vehicles and appliances; however, in the past link chainssuitable for these various fields have been too expensive for manyapplications, have not been sutficiently reliable, or have requiredexcessive service to maintain them in satisfactory operating condition.The cost of the initial installation and the replacement and servicerequirements have limited the use of the conventional link chain of theforegoing type. It is therefore one of the principal objects of thepresent invention to provide a relatively simple and easily fabricatedlink chain of the aforesaid construction which is basically stronger andmore wear resistant than the conventional link chain, and which can befabricated from standard rolled bar stock on conventional or standardmetal fabricating machinery.

Another object of the invention is to provide a chain of the aforesaidtype, the links of which are fabricated from rolled steel sheet, bar orplate stock, by a coining or forging operation, in which the grain ofthe stock is arranged parallel to the axis of the bushing, i.e.transverse to the lines of force to which the final chain is subjectedin transmitting power and transverse to the shoulders at each end of thebushing.

Still another object of the invention is to provide a link chain, theparts of which are fabricated completely from steel bar stock withoutany drilling, boring or other machining operation, and which can befully assembled by simple swaging operations.

Further objects and advantages of the present invention will becomeapparent from the following description and accompanying drawings,wherein:

FIGURE 1 is a perspective view of a link chain embodying the presentinvention;

FIGURE 2 is a perspective view of a modified form of a link chainembodying the present invention;

FIGURE 3 is a perspective view giving the details of the preferredembodiment of the present invention;

FIGURE 4 is an exploded perspective view of a modified form of thepresent invention;

FIGURE 5 is a fragmentary cross sectional view of one of the links ofthe present link chain, the section being taken on line 55 of FIGURE 1;

FIGURE 6 is a perspective view of a fully formed bushing prior to itsbeing assembled in the chain construction;

3,324,737 Patented June 13, 1967 FIGURE 7 is a perspective view of ablank from which the final bushing is made;

FIGURE 8 is a perspective view of a series of blanks and partiallyformed bushings, illustrating the steps performed in the bushing formingoperation;

FIGURE 9 is a perspective view of the strip, blanks and final bushingillustrating a method in which the bushing is formed;

FIGURE 10 is a perspective view of a strip, blanks and final bushingillustrating a modified form of the method of forming the bushing;

FIGURE 11 is a perspective view of a strip, blanks and final bushingillustrating a further modified form of the method of fabricating thebushing; and

FIGURE 12 is a fragmentary cross sectional view of the links similar tothat shown in FIGURE 5, illustrating the advantages of the constructionof the links of the present chain.

Referring more specifically to the drawings, numerals 10, 10' and 10"designate the primary links of my chain, and numerals 12 and 12'designate secondary links of the chain, the primary and secondary linksbeing connected to one another by pins 14, 16, 18 and 19 extendingthrough the ends of the aforesaid links, as will be more fully describedhereinafter.

Primary links 10, 1t) and 10" consist of side bars 20 and 22 heldrigidly in spaced relation by bushings 24 and 26 secured in holes atopposite ends of the respective side bars. Side bars 20 and 22 arepreferably stamped from rolled sheet or bar material, and the holes 28in opposite ends thereof are preferably pierced from the bars during thestamping operation, the two holes being generally cylindrical in shape,though a recess, groove or other configuration may be provided in theedge of the holes for securing bushings 24 and 26 in place.

The bushings are formed from the bar or sheet material into acylindrical structure, such as that shown in FIGURES 4 and 6, from ablank such as that shown in FIGURE 7. The blanks form the cylindricalbody portion 32 with the two ends of the blank being merely butte-dtogether, is illustrated at numeral 34. Since in the present chainconstruction the bushings do not rotate, a completely closed jointbetween the two ends is not required. The modified form of chainconstruction shown in FIGURES 2 and 4 consists of a series of onlyprimary links 40 having side bars 42 and 44 rigidly connected to oneanother by bushings 46 secured in holes 48 in one end of the two bars.The links 40, 4t) and 40" are identical in size, shape and construction,and the various links are connected to one another by pins 50 extendingthrough holes 52 and 52' in the opposite ends of the side bars 42 and44. The bushings may be the same in any one of the embodiments of theinvention thus far described and consist of a cylindrical body 32,reduced diameter portions 60 and 62 on opposite ends of the body andjoined integrally therewith, and a hole 64 extending axially through thebody 32 and reduced diameter portions 60 and 62. s

In the embodiment of the invention illustrated in FIGURE 3, which isbasically the same as the structure shown in FIGURE 1, a notch 66 isprovided in each of the two side bars 20 and 22, and, after the bushinghas been assembled between the two bars with reduced diameter portions60 and 62 extending into and through holes 28, the reduced diameterportions are swaged sufiiciently to cause the metal thereof to flow intonotches 66, as shown in the assembled link of FIGURE 3. After thebushings have been assembled between the side bars and the ends of thebushings swaged into the recesses of the side bars, the bushings arelocked rigidly in place in holes 23 and the side bars are firmly securedto the ends of the bushings. After the bushings have been assembled inthis manner with the slot 34 between the ends of body 32 facingoutwardly, the side bars 12 are assembled externally of side bars 20 and22, respectively, and secured in place by pins 14, 16, 18 and 19, asillustrated in FIGURE 1. The ends of the pins are then swaged orotherwise upset to expand them so that they firmly engage the metaldefining the holes in the ends of side bars 12, thereby rigidly holdingthe side bars 12 in place against the ends of side bars 20 and 22. Whenthe links have been assembled in the foregoing manner, the chain isready for use and the primary links 10, and 10" pivot freely on pins 14,16, 18 and 19 extending through holes 28 of the side bars and holes 64of the bushings.

One of the primary features of the present invention is the result ofthe manner in which the bushings of the present chain are formed. Themethod, which may be either a hot or cold operatioin, is illustrated inFIGURE 8 wherein a strip of sheet metal 70 is fed into a stamping orblanking machine. As the strip passes through the machine, the twoopposed notches 72 and 74 are first formed by blanking out the materialand leaving a neck 76 therebetween. The next operation performedconsists of coining or forging transverse grooves 78 and 80 in the twoedges of the blank 82 created by the series of notches 72 and 74.Thereafter, a series of rolling or cupping operations is performed,consisting of the individual steps designated by numerals 84, 86, 88, 90and 92, in which the blanks 82 are progressively rolled axially untilthe two ends 94 and 96 are in contact with one another. In the finalstages of the operation, a mandrel is inserted in hole 64 of the nearlycompleted bushing, and the connecting neck 102 is removed from theblanks of steps 90 and 92, thus detaching the formed bushing from theconnected series of partially for-med blanks. The mandrel reciprocatesfrom the position indicated by broken lines to the position shown insolid lines, and either stripping block 104 moves axially on the mandrelor the mandrel retracts through the stripping block to eject the bushingillustrated in broken lines thereon from the mandrel. The mandrel inconjunction with the press performs the final shaping and sizingOperation, and the bushing as it is ejected from the mandrel is fullyformed ready to be assembled in the chain structure between the sidebars 20 and 22, as previously described.

One of the principal features of the present invention is theorientation of the grain or crystalline structure of the metal formingthe bushings. The transverse arrangement of the grain in the bushing,i.e. the orientation of the grain in a direction axial to the axis ofthe bushing, is obtained by the method employed in the fabrication ofthe bushing. The bushings are formed from blanks lying crosswise of thedirection in which the strip of sheet material was rolled, the blanksbeing rolled or formed axially lengthwise of the strip; thus thegreatest strength of the metal in the bushing is utilized where it willproduce the greatest strength in the final chain link. FIGURE 12illustrates the direction of forces applied to the bushing in use andshows diagrammatically at numerals 109 the orientation of the grain inthe bushing. Thus, it is seen that the grain lying axially with the axisof the bushing is transverse to the lines of forces applied to thechain, as indicated by numeral 111 in sprocket tooth 113. This greatlystrengthens the bushing, particularly at the greatest reduced diameterportions 60 and 62 which are subjected to the full force applied by theside bars to the bushing.

FIGURE 9 illustrates a modified form of the method employed in formingthe present bushing, the method consisting in partially forming theblanks 110, 112 and 114 from a strip of sheet or bar material 116. Thefirst step consists in coining or forging a groove 118, and the secondstep consists in severing the two adjacent blanks in the middle of thegroove, thus providing shoulders 120 and 122 on the edges of the blanksfor forming the reduced diameter portions. After the blank has beenformed in the foregoing manner, it is rolled by any suitable rolling orcupping operation until the ends 124 and 126 are in abutment, asillustrated by numeral 128.

A further modified method for forming the present bushing is illustratedin FIGURE 10, in which blanks 130 are severed from a strip of sheetmaterial 132 without any coining, forging or other forming operationhaving been performed on the blank before it is severed from the strip.Thereafter, the blank, as illustrated at numeral 134, is coined orforged to form shoulders 136 and 138 for forming the reduced diameterportion of the final bushing. The bushing is then rolled, causing ends140 and 142 to abut one another, as indicated at numeral 144.

A further modification in the method of fabricating the bushing isillustrated in FIGURE 11. This method may be substantially the same aseither of the two illustrated in FIGURES 9 and 10 and could be embodiedin the method illustrated in FIGURE 8. The primary difference in themodified method illustrated in FIGURE 11 and those previously describedconsists in blanking the blanks for the bushings at an angle, forexample 45, to the direction of the grain, and thereafter forming thebushing, the arrows indicating the orientation of the grain. Thisoperation consists in severing a series of blanks 150 from a strip ofmaterial from sheet or plate material 152 and thereafter formingshoulders 154 and 156 from the severed blank. The blanks are then rolledby a forming operation to the position shown with the ends 158 and 160abutting one another, as illustrated at numeral 162. The bushing withthis type of grain orientation may under certain conditions have optimumstrength and maximum wear.

After the bushings have been formed by the foregoing method or any oneof the modifications, the side bars 20 and 22 are assembled on reduceddiameter portions 60 and 62, and a portion of each end of the bushing isswaged into recesses 66. The recess shown in FIGURE 3 has smooth orrounded side walls, whereas the recess in FIGURE 4 has substantiallyradially extending side walls, the only significant advantage betweenthe two forms of notches being in the greater ease with which thenotches shown in FIGURE 4 can be formed by the conventional stampingoperation. In smaller size links the holes 28 may be round, i.e.,without either type of notches 66 since the smaller bushings do not tendto rotate in the holes. In any of the embodiments described herein, boththe bushings and side bars may be fabricated by either hot or coldoperations and the two joined, i.e. the ends of the bushing expanded inthe holes in the side bars,

7 by hot or cold operations, or any combination thereof.

While several modifications of the present link chain have beendescribed herein and a method with certain variations has beenillustrated, changes may be made in both the construction of the chainand in the method without departing from the scope of the invention.

I claim:

1. A link chain, comprising two elongated side bars having a hole ineach end with a rounded notch in the side thereof and being spaced inparallel relation to one another, a steel bushing between said side barsat each end thereof, each of said bushings having an axially positionedhole therethrough and an elongated cylindrical body portion with anaxially positioned slit along one side, a reduced diameter portion ateach end thereof forming annular shoulders engaging the internal side ofsaid bars adjacent the holes therein, each of said reduced diameterportions extending into the hole in one end of said side bars and havinga deformed portion extending into the respective notch, the crystallinestructure in the steel of said bushings being oriented in the directionparallel with the axis of said bushing and being continuous from saidcylindrical portion into said reduced diameter portions, a pair of barsexternally of said first mentioned bars and having holes near one endthereof in alignment with the hole in one of said bushings, and a pinextending through the hole in said one bushing and the holes in saidlast mentioned bars.

2. A link chain, comprising two side bars having a hole in each end witha notch in the side thereof and being spaced in parallel relation to oneanother, a steel bushing between said side bars at each end thereof,each of said bushings having an axially positioned hole therethrough andan elongated cylindrical body portion with an axially positioned slitalong one side, a reduced diameter portion at each end thereof formingannular shoulders engaging the internal side of said bars adjacent theholes therein, each of said reduced diameter portions extending into thehole in one end of said side bars and having a deformed portionextending into the respective notch, the crystalline structure in thesteel of said bushings being oriented in the direction substantiallyparallel with the axis of said bushing and being continuous from saidcylindrical portion into said reduced diameter portions, a pair of barsexternally of said first mentioned bars and having holes near one endthereof in alignment with the hole in one of said bushings, and a pinextending through the hole in said one bushing and the holes in saidlast mentioned bars.

3. A link chain, comprising two side bars having a hole in each end witha notch in the side thereof and being spaced in parallel relation to oneanother, a metal bushing between said bars at each end thereof, each ofsaid bushings having an axially positioned hole 'therethrough and anelongated cylindrical body portion with an axially positioned slit oneside, a reduced diameter portion at each end thereof forming annularshoulders, each of said reduced diameter portions extending into thehole in one end of said side bars and having a deformed portionextending into the respective notch, the grain in the metal of saidbushings being oriented in the direction parallel with the axis of saidbushing and being continuous from said cylindrical portion into saidreduced diameter portions, a pair of bars externally of said firstmentioned bars and having holes near one end thereof in alignment withthe hole in one of said bushings, and a pin extending through the holein said one bushing and the holes in said last mentioned bars.

4. A link chain, comprising two side bars having a hole in each end, ametal bushing between said side bars, said bushing having an elongatedcylindrical body portion with an axially positioned slit along one sideand an axial hole therethrough, a reduced diameter portion on each endof said bushing disposed in the respective hole in said side bars andforming annular shoulders, the crystalline structure in the metal ofsaid bushing being oriented in the direction substantially parallel withthe axis of said bushing and being continuous from said cylindricalportion into said reduced diameter portions, a pair of bars externallyof said first mentioned bars and having holes near one end thereof inalignment with the hole in one of said bushings, and a pin extendingthrough the hole in said bushing and holes in said last mentioned bars.

5. A link chain, comprising two side bars having a hole in each end witha notch in the side thereof, a steel bushing between said side bars,said bushing having an elongated cylindrical body portion with anaxially positioned slit along one side and an axial hole therethrough, areduced diameter portion on each end of said bushing disposed in therespective hole in said side bars and forming annular shoulders engagingthe internal side of said bars adjacent the holes therein, thecrystalline structure in the steel of said bushing being oriented in thedirection substantially parallel with the axis of said bushing and beingcontinuous from said cylindrical portion into said reduced diameterportions, a pair of bars externally of said first mentioned bars andhaving holes near one end thereof in alignment with the hole in one ofsaid bushings, and a pin extending through the hole in said one bushingand the holes in said last mentioned bars, said last mentioned barshaving sections offset inwardly with holes near the free end thereof forreceiving a bushing.

6. A link chain, comprising two side bars having a hole in each end, ametal bushing between said side bars, said bushing having an elongatedcylindrical body portion with an axially positioned slit along one sideand an axial hole therethrough, a reduced diameter portion on each ofsaid bushing disposed in the respective hole in said side bars andforming annular shoulders, the crystal line structure in the metal ofsaid bushing being oriented in the direction substantially parallel withthe axis of said bushing, a pair of bars externally of said firstmentioned bars and having holes near one end thereof in alignment withthe hole in one of said bushings and being continuous from saidcylindrical portion into said reduced diameter portions, and a pinextending through the hole in said one bushing and the holes in saidlast mentioned bars, said last mentioned bars having sections offsetinwardly with holes near the free end thereof for receiving a bushing.

References Cited UNITED STATES PATENTS 373,983 11/1887 Jeffrey 74255528,622 11/1894 Teale 74255 1,221,617 4/1917 Sorber 74255 1,308,8437/1919 Davis 74255 1,402,766 1/1922 Hay 74255 1,925,055 8/1933 Mize74255 2,105,048 1/1938 Lauenstein et al. 74255 X DAVID J. WILLIAMOWSKY,Primary Examiner.

I. A. WONG, Assistant Examiner.

4. A LINK CHAIN, COMPRISING TWO SIDE BARS HAVING A HOLE IN EACH END, AMETAL BUSHING BETWEEN SAID SIDE BARS, SAID BUSHING HAVING AN ELONGATEDCYLINDRICAL BODY PORTION WITH AN AXIALLY POSITIONED SLIT ALONG ONE SIDEAND AN AXIAL HOLE THERETHROUGH, A REDUCED DIAMETER PORTION ON EACH ENDOF SAID BUSHING DISPOSED IN THE RESPECTIVE HOLE IN SAID SIDE BARS ANDFORMING ANNULAR SHOULDERS, THE CRYSTALLINE STRUCTURE IN THE METAL OFSAID BUSHING BEING ORIENTED IN THE DIRECTION SUBSTANTIALLY PARALLEL WITHTHE AXIS OF SAID BUSHING AND BEING CONTINUOUS FROM SAID CYLINDRICAL POR-